Energy control systems provide sophisticated, centralized control of loads in building electrical systems. The simplest types of energy control systems, such as triac light dimmers, operate by directly manipulating the AC current delivered to the loads. A serious disadvantage of such systems is that all loads downstream from the control station are affected, thus precluding control of the loads on an individual basis.
More advanced types of energy control systems provide individualized control of loads through communication between a centralized control station and the loads. The control station includes a transmitter for sending commands to the loads, and the loads contain receiver circuitry for accepting commands sent by the control station. The shortcomings of existing energy control systems become problematic when attempting to implement remote switching by which one or more loads can be controlled from multiple physical locations within a room or given area. Any provision for control of the loads from locations remote from the control station typically requires special communication wires and, in some cases, dictates that the control station be installed at a specific location in the branch circuit. Other options include employment of multiple central control stations and use of wireless or powerline communication methods to relay commands from the remote switches to the control station. Either way, the resulting systems tend to be materially expensive, difficult and time-consuming to install, and ill-suited for retrofit applications in conventional electrical systems. Consequently, deployment of such systems has been largely limited to high-end industrial and business applications.
It is therefore apparent that a need exists for a cost-effective energy control system that provides full remote control capability and that can be easily installed in conventional electrical systems without a need for additional wiring or complicated installation procedures. Such a system would represent a considerable advance over the prior art.